SplitAtlas

LG / Multi F R-32

LG Multi F 18k R-32 208/230V 2-Zone Mini-Split

Certified capacity
18,000 BTU/h[2]
SEER2
22.5 SEER2[2]
Heating floor
-4 F[1]
Voltage
230 V[1]
Install path
Professional install

The LG Multi F 2-Zone 18k (KUMXB181A) is an efficient multi-zone condenser - a certified nominal SEER2 of 22.5 (all-non-ducted) on current R-32 refrigerant, feeding two indoor heads from one 208/230V outdoor unit. Like the rest of LG's multi-zone line it is stocked at retail, so you can buy the equipment (professional installation still applies).

ENERGY STAR certified, with a 5F heating figure slightly above its 17F one. A strong value-and-efficiency two-zone.

2 zonesProfessional installCurrent

Refrigerant generation

R-32 - current-generation refrigerant

Dealer-installation warranty note

Buying online can keep warranty coverage only when the seller is expressly authorized by LG; confirm that status and the qualified installation path before purchase.

Installation condition: The online source must be expressly authorized by LG; the system must also satisfy LG's qualified-system installation terms.

Dealer path: Expressly authorized LG source with qualified installation by a trained, licensed HVAC contractor under LG warranty terms.

Paid link

$1,973 / Checked Jul 28, 2026

$1,973 at HVACDirect

This system's warranty depends on licensed installation — get quotes from installers in your area.

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Error Codes
LG Multi F 2-Zone 18,000 BTU R-32 208/230V (KUMXB181A)

Image: LG

Data completeness: 97%
Last sourced
Jul 28, 2026

SplitAtlas score

8.0 / 10

Methodology
Cooling efficiencyAbove average

(22.5 SEER2) among 18k systems

Heating efficiencyBelow average

(9.8 HSPF2) among 18k systems

Cold-weather performanceBottom quartile

(5F certified capacity: 71.8% of the 47F rating; -4 F heating floor) among 18k systems

WarrantyTop quartile

(10 yr parts / 10 yr compressor) across the catalogue

Feature setBelow average

(4 verified features) across the catalogue

Price-to-performanceBelow average

($1,973 median retail) among 18k systems

Documentation & partsBelow average

(7 manuals; spec sheet) across the catalogue

Not evaluated

  • Installation accessibility — not applicable (professional install)N/A

    professional install - DIY-accessibility not applicable

Key ratings

Rated cooling

18,000BTU/hNon-Ducted Indoor Units[2]

Rated heating

22,000BTU/hNon-Ducted Indoor Units[2]

Buyer review snapshot

Best for / skip if

Best for

  • 2-zone projects in the 18k outdoor capacity class.
  • High-efficiency shortlists; SEER2 is 22.5.

Install difficulty

Complex professional install
  • Electrical: 230V; MCA 16.1 A; breaker/fuse 20 A.
  • Line set: connection type not sourced; precharged 65.6 ft; max 164 ft.
  • 2-zone condenser; indoor-head matching and branch layout are part of the job.

Alternatives

Availability and price context

  • Last seen at HVACDirect on Jul 28, 2026: $1,973.00. Open the listing for today's price. Warranty condition: The online source must be expressly authorized by LG; the system must also satisfy LG's qualified-system installation terms.

Purchase channel policy

LG allows the online-purchase path only when the online source is expressly authorized by LG; an online purchase from a non-authorized source voids the limited warranty.

Warranty impact
The limited warranty is void and LG has no liability when the system is purchased online from a source not expressly authorized by LG.
Installation condition
The online source must be expressly authorized by LG; the system must also satisfy LG's qualified-system installation terms.
Authorized channel
Expressly authorized LG source with qualified installation by a trained, licensed HVAC contractor under LG warranty terms.

Buying online can keep warranty coverage only when the seller is expressly authorized by LG; confirm that status and the qualified installation path before purchase.

Compare online-purchase warranty rules by brand

Source: LG Electronics U.S.A., Inc.: LG R32 Residential / Light Commercial Systems Warranty Card; retrieved Aug 15, 2026.

Source date

Model data sourced
Jul 28, 2026
Page reviewed
Jul 28, 2026
Source-backed records
4
Newest source retrieved
Jul 28, 2026

Warranty tiers

Base
5 yr parts / 7 yr compressor - standard coverage
Registered
10 yr parts / 10 yr compressor - registration within 60 days of startup, by an installer with current LG training and an HVAC license

The score uses Registered. Additional published terms are shown for reference and not counted in the score.

Review methodology

Model context

Installation context
Multi-zone low-load behavior depends on the indoor heads and how many zones are calling at once.

Strengths

  • Efficient cooling: certified nominal SEER2 22.5 / EER2 13.5 / HSPF2 9.8, ENERGY STAR certified.
  • Buyable equipment (stocked and priced at retail), not dealer-only, on current R-32.
  • Two rooms from one outdoor unit and one circuit.
  • LG's inverter platform and dealer service network.

Weaknesses

  • Professional installation still required - it is equipment you buy, not a DIY kit.
  • Standard Multi F: for guaranteed deep-cold heating, the LGRED version of the 2-zone adds LG's low-temperature heating.
  • Two zones only; three or more rooms need a larger condenser.

Climate suitability

Minimum heating ambient
-4 F[1]
Certified heating at 5F
15,800 BTU/hNon-Ducted Indoor Units[2]
Rated heating at 17F
14,800 BTU/hNon-Ducted Indoor Units[2]
Rated heating at 47F
22,000 BTU/hNon-Ducted Indoor Units[2]

Specifications

Show
Manufacturer
LG
Brand
LG
Product line
Multi F R-32
Model number
KUMXB181A
Indoor unit model
Depends on the indoor units you choose
Outdoor unit model
KUMXB181A
Number of zones
2
Max indoor units
2 units[1]
Rated cooling capacity
18,000 BTU/hNon-Ducted Indoor Units[2]
Rated heating capacity
22,000 BTU/hNon-Ducted Indoor Units[2]
Voltage
230 V[1]
MCA
16.1 A[1]
Maximum fuse or breaker size
20 A[1]
Breaker needed
not published
SEER2
22.5 SEER2Non-Ducted Indoor Units[2]
EER2
13.5 EER2Non-Ducted Indoor Units[2]
HSPF2 (Region 4)
9.8 HSPF2Non-Ducted Indoor Units[2]
HSPF2 (Region 5)
Varies by indoor-unit combination
COP
not published
COP at 47F
not published
COP at 5F
2.2 COPNon-Ducted Indoor Units[2]
Minimum outdoor heating temperature
-4 F[1]
Minimum outdoor cooling temperature
14 F[1]
Maximum outdoor temperature
118 F[1]
Indoor noise range
Depends on the indoor units you choose
Outdoor noise rating
54 dBA[1]
Indoor weight
Depends on the indoor units you choose
Outdoor weight
102.7 lb[1]
Refrigerant
R-32[2]
Refrigerant charge
not published
Manufacturer coverage
not published
Line-set size
1/4 in x 2 liquid / 3/8 in x 2 suction
Included line-set length
Depends on the indoor units you choose
Maximum line-set length
164 ft[1]
Max line set per indoor
82 ft[1]
Maximum elevation difference
49.2 ft[1]
Max height between indoor units
24.6 ft[1]
Wi-Fi support
Depends on the indoor units you choose
Energy Star status
ENERGY STAR certified[3]
AHRI certification number
214848481Non-Ducted Indoor Units[2]
Warranty
Base: 5 yr parts / 7 yr compressor (standard coverage); Registered: 10 yr parts / 10 yr compressor (registration within 60 days of startup, by an installer with current LG training and an HVAC license). Score uses Registered.. Standard 5-year parts and 7-year compressor coverage; qualified registered installations extend to 10 years total parts and compressor coverage.
Install path
Professional install
Retail price
$1,973.00
Available retailers
HVACDirect
Manual links
AHRI public detail 214848481, LG Multi F R-32 combination data manual, ENERGY STAR exact row 214848481, LG Multi F R-32 current DDepot product page, KUMXB181A LG Multi F R-32 submittal, LG R32 Residential / Light Commercial Systems Warranty Card
Specification sheet
KUMXB181A LG Multi F R-32 submittal
Last sourced date
Jul 28, 2026

Retail purchase context

Dealer-installation warranty note

Buying online can keep warranty coverage only when the seller is expressly authorized by LG; confirm that status and the qualified installation path before purchase.

Installation condition: The online source must be expressly authorized by LG; the system must also satisfy LG's qualified-system installation terms.

Dealer path: Expressly authorized LG source with qualified installation by a trained, licensed HVAC contractor under LG warranty terms.

Some retailer links may earn us a commission at no extra cost; paid relationships never change scores or recommendations. Affiliate disclosure

Paid link

Dealer-installation warranty note

Buying online can keep warranty coverage only when the seller is expressly authorized by LG; confirm that status and the qualified installation path before purchase.

$1,973 at HVACDirect

$1,973 / Checked Jul 28, 2026

Compatible indoor units

This is an outdoor unit. You choose its indoor heads separately - up to the maximum this condenser supports - and you can mix room sizes and styles across the zones. The models below are the heads this unit is documented to pair with.

  • Concealed ducteds

    9k, 12k

    Model numbers
    • 9k: KNMKB091A
    • 9k: KNUJB091A
    • 12k: KNMKB121A
    • 12k: KNUJB121A

  • Four-way ceiling cassettes

    7k, 9k, 12k

    Model numbers
    • 7k: KNMDB071A
    • 9k: KNUDB091A
    • 12k: KNUDB121A

  • One-way ceiling cassettes

    7k, 9k, 12k

    Model numbers
    • 7k: KNMFB071A
    • 9k: KNUFB091A
    • 12k: KNUFB121A

Sizing note: do not just add up the rooms. Multi-zone condensers have a maximum total connected capacity, and connecting more head capacity than the unit is rated for is a common installer mistake that hurts efficiency and comfort. Match total head capacity to the condenser's rating.

Electrical requirements

Show
Voltage
230 V[1]
Voltage range
208/230V[1]
Phase
1[1]
Frequency
60 Hz[1]
MCA
16.1 A[1]
Breaker needed
not published
Maximum breaker size
20 A[1]
Maximum fuse size
not published
Maximum cooling current
not published
Maximum heating current
not published
Manufacturer wire notes
not published

Installation considerations

Show
Liquid line
1/4 in x 2[1]
Suction line
3/8 in x 2[1]
Line connection type
not published
Precharged length
65.6 ft[1]
Included line-set length
Depends on the indoor units you choose
Maximum line-set length
164 ft[1]
Max line set per indoor
82 ft[1]
Max height between indoor units
24.6 ft[1]
Indoor dimensions
Depends on the indoor units you choose
Outdoor dimensions
25.594 x 34.25 x 13 in[1]
Indoor weight
Depends on the indoor units you choose
Outdoor weight
102.7 lb[1]
Drain size
not published

Related systems and guides

Frequently asked questions

Can I install the LG Multi F 2-Zone 18,000 BTU R-32 208/230V (KUMXB181A) myself, or do I need a pro?
LG Multi F 2-Zone 18,000 BTU R-32 208/230V (KUMXB181A) is built for professional installation: the line set must be flared, evacuated, and charged, which requires EPA-certified refrigerant handling. Installing it outside the manufacturer's requirements can void the warranty, so budget for a qualified HVAC installer.
Will the LG Multi F 2-Zone 18,000 BTU R-32 208/230V (KUMXB181A) keep heating in a cold winter?
The AHRI/ENERGY STAR certification lists 15,800 BTU/h of heating capacity at 5F. Rated heating operation extends down to -4 F. Certified heating efficiency is 9.8 HSPF2. Match those numbers against your climate's design temperature - in cold regions, output at 5F matters far more than the nameplate capacity measured at 47F.
What electrical circuit does the LG Multi F 2-Zone 18,000 BTU R-32 208/230V (KUMXB181A) need?
Published electrical requirements: 230 V voltage, 16.1 A minimum circuit ampacity, and 20 A maximum breaker or fuse sizing. Confirm the final circuit against the unit nameplate and local code with a licensed electrician.
How far can the outdoor unit be from the indoor head?
The published maximum line-set length from the outdoor unit to one indoor head is 82 ft. The combined piping limit across all heads is 164 ft. The outdoor unit's factory charge covers up to 65.6 ft of line; longer runs need added refrigerant. Measure the planned routing before ordering.
What warranty does the LG Multi F 2-Zone 18,000 BTU R-32 208/230V (KUMXB181A) carry?
The manufacturer publishes these warranty tiers: Base: 5 yr parts / 7 yr compressor (standard coverage); Registered: 10 yr parts / 10 yr compressor (registration within 60 days of startup, by an installer with current LG training and an HVAC license). Score uses Registered.. Registration requirements and proof of qualified installation commonly affect coverage, so read the warranty terms before install day.

Data sources

Show
  1. LG Electronics U.S.A., Inc.: LG Multi F R-32 official technical documents for KUMXB181ASourced - manufacturer technical document

    Covers Frequency, electrical_spec.guaranteed_voltage_range, Maximum breaker size, Minimum circuit ampacity, Phase, Voltage and more

  2. Air-Conditioning, Heating, and Refrigeration Institute: AHRI public detail 214848481Sourced - AHRI directory

    Covers AHRI certification number, performance_spec.cold_climate_designation, Rated cooling capacity, COP at 5F, EER2, Rated heating capacity and more

  3. U.S. Environmental Protection Agency ENERGY STAR: ENERGY STAR exact row check for AHRI 214848481Sourced - Energy Star listing

    Covers Energy Star status

  4. LG Electronics U.S.A., Inc.: LG R32 Residential / Light Commercial Systems Warranty CardSourced - manufacturer technical document

    Covers Legacy compressor warranty value, Legacy warranty value, Registered compressor warranty, Registered warranty conditions, Registered parts warranty, Base compressor warranty and more

  5. LG Multi F R-32 combination data manualSourced - manual

    Covers Manual links

Last updated

Jul 28, 2026